Display devices based on new generation of light source have become the mainstream of the market due to the advantages of large color gamut, high brightness, and high resolution. Blue light, as one of the three primary colors, is an indispensable part of the display system. Its parameters, such as wavelength, spectral width, brightness affect the color gamut of the display system from different aspects. Strong blue light can damage the retinal cells of the human eye and affect the biological rhythm. Therefore, it is needed to consider how to reduce the blue light hazard when designing the display system. Display devices, represented by mobile phones and TV are an important part for human-computer interaction. In order to reduce the blue light hazard, anti-blue hazard mode is usually used and this mode will affect the color gamut of display device. To measure the color gamut and blue light hazards in a display system with the blue light protection mode is necessary. We propose a theory of measuring the characteristic points of display devices to obtain the stereoscopic color gamut. Several mainstream mobile phones currently on the market are used as experimental samples to measure the stereoscopic color gamut and blue light hazard value. Based on the results, we propose the measurement standard of the conversion ratio between the color gamut and the blue light hazard to evaluate the quality of the anti-blue hazard mode.